The present invention is directed to a communications interface apparatus adaptable for use with a digital-analog conversion device for effecting communications from a digital device to an analog device. Specifically, in its preferred embodiment, the present invention effects communications between a data processing device and a voice-band device, such as a telephone.
The present invention receives outgoing digital signals from the data processing device, interpolates those outgoing digital signals to produce an interpolated digital signal which is converted by the digital-analog conversion device to an outgoing analog signal representative of the outgoing digital signal. The outgoing analog signal is recognizable by the analog device.
In the manufacturing of interface devices such as the present invention, separate designs are often utilized to effect different numbers of iterations of interpolation of signals received from a digital device. Often there is duplication of engineering effort in designing such variously capable interpolation circuitry.
Such duplicate engineering effort results in each newly designed digital signal processing circuit involving essentially as much design effort, and cost, as a wholly new circuit.
The present invention is designed to overcome some of the expense of duplication of engineering effort to design variously capable digital signal processing circuits.